Current research leads us to believe that nerves may play a regulatory role in dentin deposition in teeth. Reparative or response or response dentin is known to form when dentin is stimulated by a cavity, by abrasion, heat, cold or dental caries. This response dentin forms in the pulp adjacent to the stimulated zone. Resection of nerves to the teeth results in an exaggerated dentinal response to stimulation. This dentin is not limited to the area of stimulation but forms throughout the pulp. Moreover, it is altered ranging in structure from osteoid to tubular dentin. It is the purpose of the proposed study to determine if neurotrophism and/or neural conduction plays a role in dentinogenesis. It is again the aim of these studies to determine if other than inferior alveolar and cervical sympathetic nerves supply the mandibular teeth of squirrel and rhesus monkeys. Finally it is our aim to study the effects of resection of the inferior alveolar nerve on development of erupted primary and developing permanent teeth.